Update NEWS for Telemetry rework

NEWS

@@ -9,6 +9,37 @@ Zeek 7.0.0
 Breaking Changes
 ----------------
 
+- The Telemetry framework has had a major rework, and includes a number of
+  breaking changes. The biggest change is a move towards a Prometheus-first
+  model. This removes the internal aggregation of metrics from nodes onto the
+  manager node, replacing it with a Prometheus service discovery endpoint. The
+  usage of this endpoint is described in the updated documentation for the
+  Telemetry framework. Using this endpoint also requires adding a new
+  ``metrics_port`` field to each node in the cluster configuration, denoting
+  what port to connect to for each node.
+
+  All of the metrics-related script-level options, type, and methods have been
+  moved to the Telemetry framework:
+    * Option ``Broker::metrics_port` is now ``Telemetry::metrics_port``
+    * Option ``Broker::metrics_export_endpoint_name`` is now ``Telemetry::metrics_endpoint_name``
+
+  The following options have been removed:
+    * ``Broker::metrics_export_interval``
+    * ``Broker::metrics_export_topic``
+    * ``Broker::metrics_import_topics``
+    * ``Broker::metrics_export_prefixes``
+
+  The ``unit`` field has been removed from the telemetry log.
+
+  All of the ``BROKER_METRICS_*`` environment variables have been replaced with
+  ``ZEEK_METRICS_*`` versions. This is most prevalent in cluster configurations,
+  where ``ZEEK_METRICS_PORT`` should no longer be set for each node that wants
+  to output telemetry data. Instead, a new ``metrics_port`` option was added to
+  the ``node.cfg`` options and can be used to set the port number. The cluster
+  layout record defined in ``cluster-layout.zeek`` has the same option, and it
+  can be automatically populated by ``zeekctl`` during the ``install`` or
+  ``deploy`` commands.
+
 New Functionality
 -----------------